Hepar Sulphuris Calcareum, is a very interesting remedy to study given how Hahnemann used the Calcarea from the oyster shells and the pure flowers of Sulphur to prepare it. Both these remedies have a wide sphere of action, and they share many similar and opposing symptoms as individual remedies, but when brought together in one remedy, a deep acting and rapidly effective medicine came into being which suited those who seem to be hypersensitive individuals that get affected by everything in a disturbing way.

They lack vital heat on the physical level while they are very impulsively hot tempered emotionally. The oversensitivity found in this remedy, makes the person so excitable in his sufferings, that every little thing can bring on symptoms. Like being sensitive to cold, he has no endurance in the cold, he can endure much heat in the room, many degrees warmer than a healthy person ordinarily desires. This over sensitiveness on the emotional level, makes him sensitive to impressions  and to surroundings, so he might suffer with more vehemence than an ordinary person so, the impulses will overwhelm him and make him wish to kill his best friend in an instant, and this wish could come with or without a cause. 

The Hepar individual’s impulsiveness shall show up uncontrolled almost like an animal instinct without any consideration for the circumstances that he is in, so when troubled he may have an impulse to set things on fire, the mother wants to throw her baby in the fire, there is an inclination to destroy. 

Putting the hand or the foot out of bed (uncovering), will bring on symptoms in the Hepar patient, relates to us the height of his sensitivities. This symptom can be looked at as a great example of the hypersensitivity he suffers from, for basically it could be saying that the hypersensitive state of the nervous system can detect the slightest changes in the environment, kind of like Mercurius, so this is said to be a remedy that has a sphere of action in patients that have mercurial affectations.These patients have been called human barometers. Physical affectations appear with the slightest cause, the eruptions, boils, and ulcers will hurt like sharp sticks jagging through them. He is oversensitive to pain so he may faint with pain, even with slight pain. Exposure to cold will make inflammatory and rheumatic pains appear.

The contrast in the way a Hepar feels chilled on the physical level, to the way he has this impulse to set things on fire, may be reflective of his insatiable need for warmth that he lacks, and he compensates for it emotionally with these strange desires, like he wants to set things on fire, deluding the world is on fire, an impulse to set herself on fire, are all perhaps indicating the need for heat! Just like Kent mentions, that he just can’t seem to get enough of heat, so he layers up, sits in an extra warm room, more than what a normal human being can endure.

The impulsive nature may be in answer to his otherwise hypersensitive state, it displays an explosive quality, so the otherwise chilly person who is trying to take cover from slightest exposure to cold draughts has this fiery temper on the other hand that is set off at even the slightest form of provocation.

Every little thing that disturbs the patient makes him intensely angry, abusive, and impulsive. Nothing pleases; everybody disturbs. His inability to find comfort in one single state makes him restless, displeased and discontented and so he desires a constant change of persons, things, and surroundings and each new surrounding or person or thing again displease him and makes him irritated. 

-Source for all italics: Lectures on MM, by JT Kent